ABC's Tapper on 'The Outpost,' Petraeus

11/21/12 3:14 PM EST

ABC’s Jake Tapper stopped by POLITICO LIVE on Wednesday to discuss his new book “The Outpost."

Tapper, ABC News’ senior White House correspondent, said he was watching the news in 2009, just after his son was born, when he caught a report about an “unbelievable attack” on Combat Outpost Keating.

“They faced down 400 Taliban,” he said. “And it was weird because I was holding my son and hearing about eight other sons being taken from this world. And it became a mystery that I wanted to solve — why would anybody put a base there, who were these guys, what’s it like to be in such a precarious and vulnerable place facing this onslaught from Taliban fighters? And it became a real mission and cause for me, and it became this book three years later.”

Tapper also addressed the David Petraeus scandal, telling POLITICO he didn’t hear any rumblings of an affair while he was reporting. “These guys were a world away,” Tapper.

“To think about Petraeus bringing Paula Broadwell with him to Afghanistan in the context of what these guys went through in my book — it’s just unbelievable,” he said. “And it also makes me offended because, why was he bringing a biographer with him? Why wasn’t he bringing somebody to write this book, my book, telling the story of the troops?”

“It’s just so narcissistic,” Tapper said.

While Tapper noted he had covered the war in Afghanistan before taking on the project, “it was from the comfort of the North Lawn of the White House.”

“It was debating troop levels, 10,000, 40,000, you know, and those numbers, in retrospect, we bat them around in this town. It’s kind of cold,” he said.

“This book focuses on a battle in which there are eight guys who are killed,” he added. “And I could rattle off their names right now. Behind every one of those guys there’s a grieving mom or widow or brother or sister, or a child who will never know their dad. Those numbers now mean much more to me than 40,000, 30,000, and I think I have a much richer understanding of war.”